Novocaine, a new action movie starring Jack Quaid, introduces a fresh take on the superhero genre. It features a hero whose superpower actually exists.

Mild-natured Nathan “Novocaine” Caine (Nate) is catapulted into the criminal underworld when his love interest is kidnapped by bank robbers. On his quest to save her from almost certain peril, he absorbs blades and bullets. He even manages to retrieve a gun from a scorching-hot deep-fat fryer that he then uses to shoot a baddy.

The movie’s tagline is: “Meet Nathan Caine, he can’t feel pain.”

Nate’s “superpower” is a syndrome called congenital analgesia, or congenital insensitivity to pain (CIP). As the name suggests, it’s an inability to feel pain. But those who have it really do suffer. Being able to feel pain has many advantages.

A new movie action hero is immune to pain. But that real-life condition is more of a danger than a superpower

Congenital insensitivity to pain is something of a misnomer. Technically speaking, you aren’t sensitive to pain — pain is the sensation that the brain constructs from sensory information obtained from the body. This sensory information might include mechanical injuries, such as a prick from a pin or cut from a knife. Or the extremes of hot and cold temperatures, or irritant chemicals like acids coming into contact with the skin. We call these sorts of stimuli “noxious” — meaning potentially damaging to the body.

The nerve cells (neurons) that detect these stimuli are hence called nociceptors. They have an essential role in protecting the body from harm. If you step on something sharp, say, you’ll automatically move your foot away. Or if you spill something corrosive on your hand, you’ll rush to a sink to wash the substance off.

If nociceptors weren’t there or didn’t function properly, your body wouldn’t be able to generate pain and respond to it accordingly. And your hand, foot or other appendage would remain impaled, burning or sizzling away in the fryer, while you carry on, blithely unaware of the evolving damage.

This is the main reason that CIP is so dangerous though, fortunately, it is extremely rare. There are different variants of CIP, and the prevalence varies by sub-type. Congenital insensitivity to pain with anhidrosis [inability to sweat] (Cipa), for instance, has an estimated incidence of one in 125 million.

What causes the condition? In some, problems arise with the microscopic ion channels in the endings of nociceptors. These allow neurons to become activated by noxious stimulation. You could think of them as on-switches to the generation of pain. When they don’t work properly, pain cannot be perceived. In other conditions, nociceptors may fail to develop properly or die off prematurely.

The problem with CIP is that the body becomes insensitive not only to large injuries but smaller ones too. For instance, if you get bits of grit in your eyes, the natural response is to release tears and rub or blink your eyelids to clear them. If there were no pain or irritation, the debris would build up, damaging the sensitive outer regions of the eye like the cornea, potentially causing sight-threatening ulcers to develop.

And our bodies don’t just detect external dangers — they are also sensitive to what is going on inside us. If we have an inflamed appendix, a kidney stone, or a broken bone, our nervous system lets us know by generating pain. We sense something is wrong, seek medical assistance, and are treated with antibiotics, surgery and, of course, pain relief. But the consequences of overlooking illness — should you be unable to evoke pain — can be extremely dangerous.

People with CIP have been observed to ignore a wide variety of harms — from chomped-off tongues to destructive spinal abscesses, and from amputated digits to recurrent and out-of-control infections.

CIP also affects people’s ability to sense temperature, since nociception and thermal information reach the brain via the same route: the spinothalamic tract. This affects the body’s ability to detect and, therefore, respond to temperature changes. This means that patients may overheat, especially as it can affect their ability to lose heat by sweating too. This is the case in patients with Cipa.

No cure

There is no cure for the condition, but there are ways in which CIP can be managed. People with the condition need to be extremely vigilant for any signs of injury, like wounding, and to monitor their temperature to spot any hidden infections. Regular medical check-ups are also required to look for unnoticed illness and damage.

The future is uncertain, but given that the condition is genetic, gene and stem cell therapies might also be potential treatments.

So, while Nate might make the most of not feeling pain, his ability is far from being a superpower. Pain may not feel nice, but it saves lives.

`The writer is a Senior Lecturer at the School of Physiology, Pharmacology and Neuroscience at the University of Bristol in the UK`

Republished from The Conversation

Published in Dawn, ICON, April 6th, 2025